Apparatus for drying fabric

ABSTRACT

THERE IS DISCLOSED AN APPARATUS WHICH IS ADAPTED TO BE ARRANGED IN FRONT OF A CONTACT CYLINDER DRYER FOR PREDRYING, BY MEANS OF HOT AIR, FABRIC WARP CONTINUOUSLY FED TO THE CONTACT CYLINDER DRYER. THE INVENTIVE APPARATUS INCORPORATES OUTLET SLOT MEANS FOR A CURRENT OF HOT AIR, SUCH OUTLET SLOT MEANS EXTENDING THROUGHOUT THE ENTIRE WIDTH OF THE YARN FIELD AND BEING DIRECTED APPROXIMATELY PERPENDICULAR TOWARDS SUCH YARN FIELD. A SUCTION SLOT MEANS IS SITUATED AT THE OPPOSITE SIDE OF THE YARN FIELD IN THE EXTENSION OF THE OUTLET SLOT MEANS. THIS SUCTION SLOT MEANS EXTENDS THROUGHOUT THE ENTIRE WIDTH OF THE YARN FIELD AND IS DIRECTED APROXIMATELY PERPENDICULAR THERETO. FURTHER, MEANS ARE PROVIDED FOR PRODUCING AN AIR CURRENT FROM THE OUTLET SLOT MEANS TO THE SUCTION SLOT MEANS SUCH THAT THE QUANTITY OF AIR SUCKED PER UNIT OF TIME THROUGH THE SUCTION SLOT MEANS IS AT LEAST EQUAL TO THE QUANTITY OF AIR DISCHARGED PER UNIT OF TIME FROM THE OUTLET SLOT MEANS.

Sept. 20, 1971 M. WEN GER APPARATUS FOR DRYING FABRIC 3 Sheets-Sheet 1 Filed Jun 3, 1969 INVIaN m V ws-5 6 BY i M. WENGER APPARATUS FOR DRYING FABRIC Sept. 20, 1971 3 Sheets-Sheet. 2

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INVEN'H).

MIX 1/ United States Patent Oifice 8, 7/6 Int. Cl. F26b 13/06 US. Cl. 34-155 Claims ABSTRACT OF THE DISCLOSURE There is disclosed an apparatus which is adapted to be arranged in front of a contact cylinder dryer for predrying, by means of hot air, fabric warp continuously fed to the contact cylinder dryer. The inventive apparatus incorporates outlet slot means for a current of hot air, such outlet slot means extending throughout the entire width of the yarn field and being directed approximately perpendicular towards such yarn field. A suction slot means is situated at the opposite side of the yarn field in the extension of the outlet slot means. This suction slot means extends throughout the entire width of the yarn field and is directed approximately perpendicular thereto. Further, means are provided for producing an air current from the outlet slot means to the suction slot means such that the quantity of air sucked per unit of time through the suction slot means is at least equal to the quantity of air discharged per unit of time from the outlet slot means.

BACKGROUND OF THE INVENTION The present invention relates to a new and improved apparatus arranged in front or ahead of a contact cylinder dryer and serving to pre-dry by means of hot air a fabric warp continuously delivered or fed to the aforementioned cylinder dryer.

It is conventional practice, especially with sizing machines, to conduct the freshly sized warp through a socalled pre-dryer at a location between its discharge from the sizing machine and prior to its entry into a contact cylinder dryer. In contrast with the operation of cylinder dryers, in which 'the fibers are dried through direct contact with the heated cylinder or drum, the pre-drying operation, on the other hand, occurs by means of hot air or unsaturated vapor which is conducted to the wet dividing zone between the sizing machine and the contact dryer.

Belonging to the prior art technology in this particular field are the infra-red pre-dryers which, however, possess different drawbacks, some of which are quite substantial. For instance, some of these drawbacks manifest themselves through the high investment costs for the installation of such pre-dryers and the high operation costs due to the relatively short life span of the infra-red lamps and the high energy consumption.

Likewise known to the art are chamber or compartment dryers in which a hot vapor air mixture is applied to the warp which is divided into different stages or stories. Considerable drawbacks are also associated with these known pre-dryers, especially those which manifest themselves through the great service requirements which are necessary for the insertion of the dividing rods for distribution or division of the warp and which are also necessary in order to remove rupture of the fibers or yarn.

A further species of known pre-dryers is engendered by the so-called plane or horizontal dryer which operates with hot air. Such type dryers, as a practical matter, are only suitable for working with warps having a small number of yarns or yarn count. This is because upon passage of the warp through such a pre-dryer, all of the yarns of the 3,605,282 Patented Sept. 20, 1971 warp are placed into a plane which, in turn, naturally, requires a very large structural length of such a pre-dryer, and accordingly, a very great expenditure of energy for the quantity of hot air, which for high yarn counts becomes uneconomical. Additionally, such plane dryers exhibit the drawback that, especially with compact warps, the freshly sized yarns tend to bond to one another.

In addition to the specific drawbacks associated in each instance with the heretofore mentioned particular type of species of dryer arrangement common drawbacks are associated with the infra-red pre-dryers as well as also the plane dryers and the compartment dryers. One such common drawback which is experienced with all of these various types of constructional forms of pre-dryers is, for instance, that they all render difficult access to the yarns of the wet dividing zone.

For instance, in the case of the infra-red dryers servicing is rendered difficult because of the cluster of lamps which, therefore, must be constructed so that they are retractable. In the case of the compartment dryers servicing is rendered diflicult because of the very great expanse of this dryer arrangement in its length and height, and additionally, by virtue of the intense heat prevailing within the compartment during operation which has a tendency of remaining for some period of time after the pre-dryer is switched off. This, in turn, delays the prompt removal of yarn ruptures which occur during operation. Finally, in the case of the plane dryer arrangement, the servicing requirements are likewise made more difiicult because of the very large structural length of such dryers.

Furthermore, it is to be additionally mentioned that all of these various species of known pre-dryers have the disadvantage that they require a longer heat-up time and a corresponding longer cooling time. Additionally, they possess components which tend to store the pre-drying heat or thermal energy which, in turn, is dangerous since during interruptions of the operation during transport of the warp, even if the pre-dryer is simultaneously shut down, the lengthwise section of the warp which remains stationarily within the confines of the pre-dryer tends to become overdried.

Furthermore, the pre-dryer constructions which are known up to the present are additionally not very suited for a rapid responsive temperature regulation, or at the very least, are poorly suited for such, and in the case of universal machines, which should selectively operate with or without a pre-dryer, they are not readily suitable since they can only be removed with extreme difficulty.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide an improved apparatus for pre-drying a fabric warp by hot air which is continuously delivered to a cylinder dryer in a manner which effectively overcomes the aforementioned drawbacks of the prior art constructions.

Still another significant object of the present invention relates to an improved apparatus of the mentioned type which provides for an efiicient and controlled pre-drying of warp.

Still further significant objects of the present invention are the provision of an improved apparatus adapted to be arranged in front of av contact cylinder dryer for predrying by hot air fabric warp continuously fed to the contact cylinder dryer, which apparatus:

(a) effectively overcomes the aforementioned drawbacks of the prior art pre-dryers;

(b) does not require any compartment or housing enclosing the warp;

(c) does not obstruct the accessibility to or servicing of the wet dividing zone during removal of yarn ruptures and during insertion of dividing rods;

(d) possesses a short structural length, so that the warp is not guided only over very short lengths or paths; and

(e) allows for a quick accommodation of the heating conditions to different operational conditions, whether it be for the purpose of accommodation to different warps or to different warp through-passage velocities.

Now, in order to implement these and still further objects of the invention, which will become more readily apparent as the description proceeds, the inventive apparatus is generally manifested by the features that it possesses an outlet slot means for a current of hot air which extends substantially over the entire width of the yarn field and is directed approximately perpendicular towards such yarn field. Furthermore, at the opposite side of said yarn field in the extension of the outlet slot means, there is provided suction slot means. Such suction slot means extend substantially throughout the entire width of the yarn field and directed approximately perpendicular to such yarn field. Additionally, the invention contemplates the provision of means for generating an air current from the outlet slot means to the suction slot means in a manner such that the quantity of air sucked per unit of time through the suction slot means is equal to or greater than the quantity of air which is ejected per unit of time from the outlet slot means.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood, and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 schematically illustrates an installation incorporating a warp beam frame, sizing machine, apparatus for pre-drying, cylinder dryer and wind-up apparatus;

FIG. 2 schematically shows in side view details of the components associated with the pre-drying apparatus of the arrangement of FIG. 1, while omitting for convenience in illustration the other components or members not directly associated with such pro-drying apparatus;

FIG. 3 is a schematic top plan view of the apparatus for pre-drying and the cylinder dryer; and

FIG. 4 is a vertical sectional view taken through the discharge or outlet slot means of the apparatus for predrying shown in the general arrangement of installation of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Describing now the drawings, in FIG. 1, there is illustrated the course of travel of a fabric warp K which is drawn off a warp beam frame unit 1. This fabric Warp K passes through a suitable sizing vat 2 in which it is sized, and upon leaving the sizing vat 2 this warp K passes through a region conveniently designated as a wet dividing zone 3, to finally arrive at the drum means 4 of a contact cylinder dryer arrangement. Following the cylinder drying arrangement 4, is a beaming or wind-up machine 5 onto which is wound the sized and now dried warp K.

The previously described devices and the course of travel of the warp K therethrough are generally known to the textile art, therefore need not be considered in greate detail, especially since further description thereof is not necessary for understanding the underlying concepts of the invention. Additionally, the arrangement of the rollers for guiding and supporting the warp between and at these various devices, which have been illustrated in FIG. 1 without making any particular reference thereto, can also be considered to be well known to the art. In fact, for purposes of preserving clarity in illustration, they have conveniently been completely omitted from FIGS. 2 to 4.

Further, the arrangement of a hood member 6 above the cylinder dryer arrangement 4 can also be considered known to the art. This hood member 6 opens or communicates with a withdrawal channel or duct 7 in which there is housed a suitable ventilator 8. The ventilator 8, or equivalent structure, serves to withdraw the air saturated with moisture appearing at the cylinder dryer arrangement 4. Furthermore, directly after the hood member 6 within the confines of the duct or channel 7 there are arranged suitable articulated flap or valve members 9, by means of which it is possible to regulate the Withdrawal of air through the hood member 6.

Now, the apparatus for carrying out the pre-drying operation, and which constitutes the primary aspect of the present invention, will be seen to be arranged at the region of the wet dividing zone 3. Its purpose is to prevent the sticking or adhering together of the fibers or yarns of the freshly sized warp K. Additionally, this pre-drying apparatus is intended to also subject to a drying operation the flanks or sides of the yarns which are not placed into contact with the drying drums of the cylinder drying arrangement 4.

Additionally, it will be understood that the illustrated apparatus for pre-drying utilizes parts or components of the existing cylinder dryer, especially its air withdrawal duct or channel 7 and the ventilator 8. It will be seen to further encompass a withdrawal hood member 10 which is directed approximately vertically and the opening of which forms a suction slot means 11 arranged directly over the warp K and extending over the entire width of this warp and approximately directed perpendicular thereto. Continuing, it will be recognized that the upper end 10a of the hood member 10 opens into the channel or duct 7, and furthermore, between the suction slot means 11 and the opening into the duct 7 there are arranged articulated flap or valve means 12 which enable regulation or control of the passage of air through the hood member 10.

Also, it will be recognized that in the extension of the suction slot means 11, at the opposite side of the warp K directly therebeneath, there is arranged a substantially slot-shaped outlet means 13 for a current of hot air and which is directed toward the suction slot means 11. This outlet or discharge slot means 13 likewise extends approximately perpendicular to the warp K throughout the entire width thereof. Furthermore, as best observed by referring to FIG. 4, at the outlet slot means 13, there are arranged a large number of lamellae or fins 14 which are in parallelism with one another and which subdivide the outlet slot means 13 into substantially vertically extending channels 14a. It is also seen by referring to this figure that these lamellae or fins 14 are secured to a heating coil 15 extending into the outlet slot means 13.

The air current delivered to the outlet slot means 13 is produced by the ventilator or fan 8 arranged in the duct or channel 7. T 0 this end, there are operatively connected in flow communication with the duct 7, at opposite sides of this duct, and downstream of the ventilator 8 in the direction of flow, two branch channels or ducts 16 and 17. These branch ducts or channels 16 and 17 are downwardly directed at both sides of the sizing vat 2 and conducted beneath such sizing vat, to finally open into opposite sides of the outlet slot means 13, as best seen by referring to FIGS. 2 and 3. Flap or valve members 18 and 19 serve to regulate the distribution of the air current produced by the ventilator *8 between the duct 7 and the branch channels or ducts 16 and 17, respectively. Upstream of the ventilator 8, in the direction of air current flow, there is additionally provided at the duct 7 a pipe connection or stud 20 for entry of fresh air into the circulation system, whereby this fresh air infeed can be regulated by a flap or other suitable valve 21 arranged within the pipe connection 20, as best shown by referring to FIG. 1.

As will be readily apparent to those versed in the art, it is possible for all of the previously mentioned flaps or valves which control the throughflow of air to be adjustable by an appropriate motor-drive or equivalent positiom'ng control device, so that the regulation of these valves or flaps can be, if desired, rendered completely automatic.

Notwithstanding, and in fact because of, the exceptionally small spatial and energy requirements, the desired and illustrated exemplary embodiment of inventive apparatus for pre-drying a fabric warp lends itself to 'be used universally with an installation equipped with such an apparatus and a cylinder dryer.

Although the pre-drying apparatus is arranged in or connected with the venting system of the cylinder dryer, the illustrated installation can also operate without any pre-drying apparatus. This would then be the case if the air flow directing flaps 18 and 19 assumed the position shown in FIG. 3 in which they close the branch channels or ducts 16 and 17, respectively, and the flaps or valves 12 and 21 are also closed.

In this position the ventilator or fan 8 sucks air via the hood member 6 of the cylinder dryer and conducts this air through the channel or duct 7 into the surrounding atmosphere. Hence, the pre-dryer apparatus is not in operation.

On the other hand, when a combined operation is to be undertaken, which is generally more oftentimes desired, by undertaking a more or less pronounced opening of the deflecting or control flaps 1-8 and 19, a portion of the air conducted away through the duct 7, which can be more or less enriched with fresh air by appropriate opening of the flap means 21, is conducted through the branch channels or ducts 16 and 17 to the outlet slot means 13. By simultaneously opening the flap means or members 12, the ventilator 8 also sucks air through the suction slot means 11. Consequently, a current or stream of hot air exists between the outlet or discharge slot means 13 to the suction slot means 11, since the portion of the air coming out of the hood member 6 is hot and the air is additionally further heated by the heating coil means 15 directly prior to contacting the warp K. By virtue of the provision of the lamellae or fins 14, the air conveyed through the branch channels 16 and 17 to the outlet slot means 13 is uniformly divided and distributed over the entire range of the outlet slot means. Furthermore, a directed air current leaves this outlet slot means 13, the air jets of which form a plane which is perpendicular to the fibers or yarns of the throughpassing warp K. This phenomenon is further supported according to the invention in that according to one important aspect of the described apparatus, the flow conditions are adjusted by means of the flap members and the fins in such a manner that the quantity of hot air sucked per unit of time through the suction slot means 11 is greater than the quantity of air which is ejected or discharged from the outlet slot means 13 per unit of time. Consequently, there exists a heating phase which acts throughout the yarn field with a minimum of losses in thermal energy due to lateral radiation.

This hot air current acts, in the first instance, upon the flanks or sides of the yarns, exactly upon those locations which are neglected during the drying operation in the subsequently arranged cylinder dryer arrangement 4. The pre-drying of just these flanks or sides of the yarns can, however, depending upon the make up of the warp and especially for thick warps, be of decisive importance in order to prevent the sticking or adhering together of the yarns of the warp.

Additionally, by virtue of the action of this heat current, fibers which protrude or project away from the warp threads are directly pressed against the threads or yarns, or at the very least, however, parallely directed in the direction of the air current, and specifically, in such a way that in the cylinder dryer arrangement, when in contact with the drums thereof, these protruding fibers are placed against the warp threads or yarns.

From the preceding description, it will also be apparent that the described apparatus can be quickly and precisely adjusted, whereby the heating efficiency and the air quantity can be adjusted or regulated equally well for slow operations as well as for normal speed operations. In the event that the warp is stopped because of a breakdown in the operation, then, by switching off the predryer, the air current can momentarily be interrupted. As there are neither present chamber walls nor housing walls, there is also, during shut down of the pre-dryer, no heat radiation onto the warp by heated metallic parts and, thus, there does not occur any overdrying of the warp section which is at standstill in the pre-dryer.

It should be apparent from the foregoing detailed description, that the objects set forth at the outset to the specification have been successfully achieved.

What is claimed:

1. An apparatus adapted to be arranged in front of a contact cylinder dryer for pre-drying by means of hot air fabric warp continuously fed to the aforesaid contact cylinder dryer, comprising means defining outlet slot means for a current of hot air, said outlet slot means extending throughout substantially the entire width of the yarn field and being directed approximately perpendicular to such yarn field, means defining a suction slot means situated at the opposite side of said yarn field in the extension of said outlet slot means, said suction slot means extending throughout substantially the entire width of said yarn field and being directed approximately perpendicular to said yarn field, said suction slot means and said outlet slot means being vertically aligned, fin means in substantial parallelism with one another for subdividing said outlet slot means into vertical channels, so that during operation a directed air current forms between said outlet slot means and said suction slot means, the air jets of which are disposed in a plane which is substantially perpendicular to the yarns of the throughpassing warp, and means for producing an air current from said outlet slot means to said suction slot means such that the quantity of air sucked per unit of time through said suction slot means is at least equal to the quantity of air discharged per unit of time from said outlet slot means, said means defining said suction slot means incorporating a suction hood member, hood means arranged over said contact cylinder dryer, a withdrawal duct means communicating with said hood means, said suction hood member opening into said withdrawal duct means of said hood means, air delivery conduit means branching off of said withdrawal duct means for said contact cylinder dryer, said air delivery conduit means communicating with said outlet slot means, and air deflecting flap means located at the region where said air delivery conduit means branches oif from said withdrawal duct means for regulating the quantity of air flowing through said air delivery conduit means and branched off from the air current flowing through said withdrawal duct means.

2. An apparatus as defined in claim 1, further including articulated flap means arranged between said hood means of the contact cylinder dryer and the opening of said suction hood member into said withdrawal duct means, said articulated flap means being closeable for operation of the pre-drying apparatus by itself.

3. An apparatus as defined in claim 2, further including controllable air infeed opening means for fresh air communicating with said withdrawal duct means, said air infeed opening means being arranged downstream of said articulated flap means in the flow direction of the air current through said withdrawal duct means.

4. An apparatus as defined in claim 1, further including apart from said air deflecting flap means for shutting down the pre-drying apparatus during operation solely with said contact cylinder dryer, additional articulated flap means arranged in said suction hood member.

5. An apparatus as defined in claim 4, wherein regulation of said air current at said suction slot means and at said outlet slot means is respectively undertaken by means of said additional articulated flap means in said suction hood member and said air deflecting flap means provided at the branch off location of said air delivery conduit means leading to said outlet slot means.

References Cited UNITED STATES PATENTS EDWARD J. MICHAEL, Primary Examiner 

